Dice In The Darkness: Cthulhu Calls - Chapter 478: For Self? For Others?

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates

One day, I was given the mysterious power of Hwanmong.

They call him Ghost.A name whispered in fear across warzones, black markets, and underworld circles.To the world, he's a phantom—a faceless mercenary who leaves no trace but bodies in his wake.To his enemies, he’s a death sentence.To his brothers-in-arms in Graveyard, he’s family.But to himself... he's a haunted man searching for a past stolen in gunfire and smoke.After a flawless mission deep in the Eastern Province, Ghost returns to the hidden forest base he's called home for sixteen years. Yet the victory is short-lived. His foster father, the commander delivers an unexpected order:“That was your last mission.”Now, Ghost—real name Miles Sterling—must step out of the shadows of war and into a world he’s never known. Guided only by a scarred letter, a fading memory, and the voice of a woman he hasn’t seen since the day everything was taken from him.But war forged more than his body and name.Behind the mask, behind the scars, Miles has another secret.One he’s kept hidden even from his brothers in arms.He’s not just a weapon.He’s a ghost with a fortune—a hidden empire he built in silence, across borders and black markets, forged in strategy and blood.A man of many names, and many shadows.Beneath the bullets, tattoos, and silence lies a truth buried in ashes.And Ghost is about to dig it up—one letter, one enemy, one memory at a time.

After transcending to a new world, Ye Xuan miraculously obtained the Swallowing System.